This invention relates to an improved uncoupling device for use with rotary freight car couplers.
Each freight car used in the United States is required by law to be equipped with an uncoupling means which can be operated from the side of the car without the necessity of trainmen going between the cars. Therefore, cars are equipped with uncoupling levers or rods connected to the coupler and extending to the corners of the cars. By manipulation of the uncoupling lever, rotary action is imparted to the bottom lock lift on the coupler causing the lock to rise and the knuckle to open.
During the last decade, the development of unit trains of rotary dump cars made it desireable to dump cars in a rotary dumper without having to uncouple the cars. This caused the development of the rotary coupler. This type of coupler is connected to the car with a special yoke which permits the coupler to revolve around a longitudinal axis through its center. It permits rotary dumping of a car without also turning over the cars to which it is coupled.
Because of this rotary action, the uncoupling lever cannot be attached to the coupler lest it becomes damaged the first time the couplers are rotated. To solve this problem, early rotary dump cars were equipped with a standard rotary coupler on one end, and a rigid coupler (non-rotary) on the opposite end. Thus, if cars are always oriented together so that a rotary coupler and a rigid coupler are always adjacent to each other, the train can be dumped without uncoupling. Since the standard coupler could have an uncoupling lever attached to it, it is always possible to uncouple the cars with this arrangement.
While the above-described system of orienting cars provides one solution to the way cars may be rotated while coupled together in a train it is apparent that the orientation of car represents an exacting and time consuming task. Thus it would be preferable, in certain situations, if a car is to be used in a unit train, that such car could be equipped with rotary couplers at both ends. This, of course, would eliminate the requirement for proper orientation of car in the train.
It was the above-described objective in mind that thought was also given to the development of an uncoupling lever device which could be used with rotary couplers and could be expected to positively insure the correct uncoupling of a car from both its adjacent cars.
It is known in the art to provide a uncoupling rod device for use with rotary couplers on freight cars in which the manually operated rod device is rotatably mounted with respect to the car body and has a portion which is adapted to be swung into contact with a rotor arm of an unlocking mechanism on the rotary coupler. For a more complete description of known devices attention is directed to U.S. Pat. Nos. 3,572,518, 3,580,400 and 3,115,973.
However, as far as applicant knows, with all previously devised devices that portion of the operating rod which is swung into contact with the rotor arm of the unlocking mechanism moves through an arc to make initial contact at the lower end of the rotor arm. As the rotor arm is swung forward by continued manual movement of the uncoupling device the portion of the device in contact with the rotor arm moves upward on this arm in a manner as seen, for example in FIG. 2 of U.S. Pat. No. 3,572,518. It will be appreciated that as this occurs there is a gradual loss of mechanical advantage which makes it increasing difficult to operate the unlocking mechanism as the coupler reaches its fully unlocked position.
It is therefore an object of this invention to provide an uncoupling rod device for a rotary coupler which permits a portion of the uncoupling rod device to engage the rotor arm at the most advantageous point throughout the full movement of rotor arm. With such an arrangement it is possible to thereby achieve maximum mechanical advantage in movement of this rotor arm.